Quieten browser init in test setup

[scjody]

This code is shared by the DE automated end to end integration tests (e2e). The information logged here is never useful to us so this adds a significant amount of noise to our tests. If it's useful to you folks (in a non-debugging context), I'd be happy to make it configurable in the Browser() constructor! @plotly/dash-core Please let me know!

Example output from a recent e2e run:

INFO     dash.testing.browser:browser.py:80 initialize browser with arguments
INFO     dash.testing.browser:browser.py:81   headless => False
INFO     dash.testing.browser:browser.py:82   download_path => /tmp/pytest-of-circleci/pytest-0/test_dds_snapshot_engine_pdf0/aws_ha_eks_download
INFO     dash.testing.browser:browser.py:83   percy asset root => /home/circleci/dds/tests/integration/tests/assets

These (or similar messages) are repeated a total of 192 times in the run above!

Contributor Checklist

• I'll test this PR to make sure it works for us on Wednesday!

[scjody]

PS the CI failures are caused by a recent change to the cryptography library. Pinning it to an older version like I'm doing here in DDS seems like a useful workaround.

(It's really unfortunate that many open source projects, including cryptography, seem to have a deep commitment to the "not my problem" mindset.)

[alexcjohnson]

💃 Thanks @scjody - those logs definitely don't need to be seen except in deep debugging.

In dash-land the cryptography issue only seems problematic on Py3.6 - presumably there's just no wheel published there? So for now I'll attempt to just restrict it before Py3.7 (which will affect 2.7 too but I'm done with Py2-specific code if at all possible!)